feat(tags): process tagfiles on the fly (#1989)

lua/telescope/builtin/files.lua

@@ -422,6 +422,9 @@ end
 
 files.tags = function(opts)
   local tagfiles = opts.ctags_file and { opts.ctags_file } or vim.fn.tagfiles()
+  for i, ctags_file in ipairs(tagfiles) do
+    tagfiles[i] = vim.fn.expand(ctags_file, true)
+  end
   if vim.tbl_isempty(tagfiles) then
     utils.notify("builtin.tags", {
       msg = "No tags file found. Create one with ctags -R",
@@ -429,20 +432,11 @@ files.tags = function(opts)
     })
     return
   end
-
-  local results = {}
-  for _, ctags_file in ipairs(tagfiles) do
-    for line in Path:new(vim.fn.expand(ctags_file, true)):iter() do
-      results[#results + 1] = line
-    end
-  end
+  opts.entry_maker = vim.F.if_nil(opts.entry_maker, make_entry.gen_from_ctags(opts))
 
   pickers.new(opts, {
     prompt_title = "Tags",
-    finder = finders.new_table {
-      results = results,
-      entry_maker = opts.entry_maker or make_entry.gen_from_ctags(opts),
-    },
+    finder = finders.new_oneshot_job(flatten { "cat", tagfiles }, opts),
     previewer = previewers.ctags.new(opts),
     sorter = conf.generic_sorter(opts),
     attach_mappings = function()